The present invention relates in general to flamon devices and in particular to a new and useful device and method of determining whether a burner flame is in an on condition, in particular a coal fired burner flame.
Equipment is known for remotely sensing whether a flame of a burner is on or not. So called flicker flamon units have been disclosed which sense the flicker frequencies that occur naturally in burner flames. In such devices, however, each burner must be analyzed to determine the optimum frequency band for that burner. It often happens that adjacent burners have similar flicker frequencies so that it becomes difficult for a remote sensor to determine whether the one or the other of the burners are on.
It is also known for the purposes of discovering the state of a burner flame, to propagate cyclic pressure waves through a burner which waves produce cyclic oscillations in the flame. Such oscillations have been discovered to produce electromagnetic variations which can be sensed using a radio antenna, as disclosed in U.S. Pat. No. 3,586,468 to Sims.
Other techniques and apparatus for sensing the presence of a burner flame are disclosed in U.S. Pat. No. 2,979,125 to Katorsky, and U.S. Pat. No. 2,460,314 to Thomson.